Nutritional Aspects of Iron in Health and Disease

Dietary iron assimilation is critical for health and essential to prevent iron deficient states and related comorbidities, such as anemia. The bioavailability of iron is limited, while its absorption and metabolism are tightly controlled to keep body iron stores within a relatively narrow range. Genetic inactivation of the iron hormone hepcidin causes hereditary hemochromatosis, an endocrine disorder of iron overload characterized by chronic hyperabsorption of dietary iron, with deleterious clinical complications if untreated. The impact of high dietary iron intake and elevated body iron stores in the general population is not well understood. Herein, we summarize epidemiological data suggesting that high intake of heme iron, which is abundant in meat products, poses a risk factor for metabolic syndrome pathologies, cardiovascular diseases, and some cancers. We discuss clinical relevance and potential limitations of data from cohort studies, as well as the need to establish causality and elucidate molecular mechanisms.